Brigid Quinn's experiences in hunting sexual predators for the FBI have left her with memories she wishes she didn’t have and lethal skills she hopes never to need again. Having been pushed into early retirement by events she thinks she's put firmly behind her, Brigid keeps telling herself she is settling down nicely in Tucson with a wonderful new husband, Carlo, and their dogs.

But the past intervenes when a man named Floyd Lynch confesses to the worst unsolved case of Brigid’s career—the disappearance and presumed murder of her young protégée, Jessica. Floyd knows things about that terrible night that were never made public, and offers to lead the cops to Jessica's body in return for a plea bargain.

It should finally be the end of a dark chapter in Brigid’s life. Except…the new FBI agent on the case, Laura Coleman, thinks the confession is fake, and Brigid finds she cannot walk away from violence and retribution after all, no matter what the cost.